Device for driving an analogue indicator, particularly a date ring

Patent metadata

Field	Value
Publication number	US-9411311-B2
Application number	US-201514637836-A
Country	US
Kind code	B2
Filing date	Mar 4, 2015
Priority date	Mar 10, 2014
Publication date	Aug 9, 2016
Grant date	Aug 9, 2016

Abstract

The timepiece movement is fitted with an analogue indicator ( 6 ), particularly a date ring including a toothing ( 18 ) mechanically coupled to a drive device, which includes a motor and a drive wheel and pinion ( 8 ) and a support for the drive wheel and pinion. This support is pivotally mounted on a main plate about a first axis and it defines a second axis, remote from the first axis, about which the drive wheel and pinion is rotatably mounted. The drive device further includes a strip spring ( 40 ) exerting a force on the support such that the meshing means of the drive wheel and pinion press against the toothing of the analogue indicator. The meshing means and the toothing have respective profiles selected such that, at least in a plurality of distinct display positions of the analogue indicator, the drive wheel and pinion and the analogue indicator mesh with each other with substantially no play under the action of the strip spring.

First claim

The invention claimed is:

1. A timepiece movement fined with an analogue indicator of a plurality of distinct data which is arranged to be held stationary at least temporarily in any one position of a plurality of distinct display positions, said analogue indicator including a toothing mechanically coupled to a drive device including a motor and a drive wheel and pinion provided with a meshing mechanism to mesh with the toothing, said drive device further including a support on which the drive wheel and pinion is mounted, said meshing mechanism formed by two pins which rise from said drive wheel and pinion,
wherein said support is mounted on a base in order to pivot about a first axis and said drive wheel and pinion is rotatably mounted on said support about a second axis distinct from the first axis, said drive device further including an elastic mechanism applying a lateral force to said support so that said meshing mechanism of the drive wheel and pinion press against the analogue indicator toothing, said meshing mechanism and the toothing including respective profiles selected such that, at least in said plurality of distinct display positions of the analogue indicator, the drive wheel and pinion and the analogue indicator mesh with each other with substantially no tangential play under the action of said elastic mechanism once each of the two ins comes in contact with the toothing.

2. The timepiece movement according to claim 1 , wherein the drive device further includes an intermediate wheel which is arranged between the motor and the drive wheel and pinion and which meshes with said drive wheel and pinion, said intermediate wheel being mounted on said pivoting support and including an axis of rotation that merges with said first pivot axis of said support.

3. The timepiece movement according to claim 1 , wherein said analogue indicator is a date ring and said toothing is an inner toothing of said date ring.

4. The timepiece movement according to claim 1 , wherein said meshing mechanism are formed by at least three pins which rise from the drive wheel and pinion.

5. The timepiece movement according to claim 4 , wherein the pins are each provided with a roller bearing.

6. The timepiece movement according to claim 4 , wherein teeth of said toothing have non-parallel flanks each defining a monotonically increasing curve relative to a central axis of the corresponding tooth towards a bottom of said toothing, and wherein a distance between two adjacent pins, where appropriate between two respective roller bearings, is arranged, in said plurality of distinct display positions of the analogue indicator, to have two points of contact between the two adjacent pins or, where appropriate, between the two respective roller bearings and respectively two flanks of a tooth, without touching the bottom of the toothing.

7. The timepiece movement according to claim 4 , wherein teeth of said toothing have non-parallel flanks each defining a monotonically increasing curve relative to a central axis of the corresponding tooth towards a bottom of said toothing, and wherein a distance between two adjacent pins, where appropriate between two respective roller bearings, is arranged, in said plurality of distinct display positions of the analogue indicator, to have two points of contact between the two adjacent pins or, where appropriate, between the two respective roller bearings and respectively two flanks of two teeth, including between them an intermediate tooth, without touching the bottom of the toothing.

8. The timepiece movement according to claim 1 , wherein said meshing mechanism are formed by only two pins which rise from said drive wheel and pinion, said two pins being aligned with the axis of rotation of said drive wheel and pinion and diametrically opposite.

9. The timepiece movement according to claim 8 , wherein the two pins are each provided with a roller bearing.

10. The timepiece movement according to claim 8 , wherein teeth of said toothing have non-parallel flanks each defining a monotonically increasing curve relative to a central axis of the corresponding tooth towards a bottom of said toothing, and wherein a distance between the two pins, where appropriate between the two respective roller bearings, is arranged, in said plurality of distinct display positions of the analogue indicator, to have two points of contact between the two pins or, where appropriate, between the two respective roller bearings and respectively two flanks of a tooth, without touching the bottom of the toothing.

11. The timepiece movement according to claim 8 , wherein teeth of said toothing have non-parallel flanks each defining a monotonically increasing curve relative to a central axis of the corresponding tooth towards a bottom of said toothing and wherein a distance between the two pins, where appropriate between the two respective roller bearings, is arranged, in said plurality of distinct display positions of the analogue indicator, to have two points of contact between the two pins or, where appropriate, between the two respective roller bearings and respectively two respective flanks of two teeth, including between them an intermediate tooth, without touching the bottom of the toothing.

12. The timepiece movement according to claim 1 , wherein said motor is an electromagnetic motor, and wherein said timepiece movement includes a control unit arranged to drive said electromagnetic motor n an accelerated mode during the change from one distinct display position to a following distinct display position.

13. The timepiece movement according to claim 1 , wherein said elastic mechanism applying a lateral force to said support is formed by a strip spring.

Assignees

• Eta Sa Mft Horlogere Suisse

Inventors

• Wyssbrod Baptist
• Christan Julien

Classifications

• G04C17/0066 Primary

  electromagnetically driven, e.g. intermittently (clocks incorporating a stepping motor G04C3/14) · CPC title

• G04B13/02 Primary

  Wheels; Pinions; Spindles; Pivots (bearings G04B31/00 {; chain wheels, spindles for chain wheels, also chains and driving weights G04B1/08}) · CPC title

• G04B13/027

  planar toothing: shape and design (adjusting the backlash of the arbors G04B35/00) · CPC title